Convex-concave roller



FIG. 1 is a perspective view of our new design for a convex-concave roller;

FIG. 2 is a front elevational view of the convex-concave roller shown in FIG. 1;

FIG. 3 is a rear elevational view of the convex-concave roller shown in FIG. 1;

FIG. 4 is a side elevational view of the convex-concave roller shown in FIG. 1;

FIG. 5 is an opposite side elevational view of the convex-concave roller shown in FIG. 1;

FIG. 6 is an end view of the convex-concave roller shown in FIG. 1; and,

FIG. 7 is an opposite end view of the convex-concave roller shown in FIG. 1. 

The ornamental design for a convex-concave roller, substantially as shown. 